1. Field of the Invention
The present invention relates generally to driving axles for use in automotive applications and, more particularly, to a driving axle cover pan equipped with an anti-lock braking system sensor.
2. Discussion of the Related Art
Many of the vehicles currently manufactured include an anti-lock braking system to provide an operator greater vehicular control while attempting to stop on surfaces having a low coefficient of friction. One type of anti-lock brake system, commonly known as a three-wall system, utilizes three speed sensors for detecting wheel lock. Typically, a three-wall system is used in conjunction with a rear wheel drive vehicle where two of the sensors are placed on the front, nondriving wheels while the third is placed on the rear driving axle. The present invention is primarily directed to the location and mount of the third sensor on the rear driving axle.
Most rear driving axles include a differential assembly rotatably supported within an axle carrier to facilitate relative rotation between a pair of output shafts. Typically, the differential assembly includes a planetary gear set having a pair of helical side gears that are splined to the ends of axle shafts. The helical side gears are meshed with paired sets of helical pinions rotatably mounted in a differential housing. In response to speed differentiation between the output or axle shafts, the torque transmitted through meshed engagement of the side gears and of the pinions generates forces causing the differential housing to rotate at a speed intermediate to the speed of the two axle shafts. Accordingly, the rotational speed of the differential housing provides an indication of the rotational speed of each of the rear wheels. As such, a tone ring of an anti-lock braking system (ABS) may be fixed to the differential housing while a sensor is fixed to the axle carrier and disposed in an aperture therethrough to become proximately located to the tone ring.
Unfortunately, mounting the ABS sensor to the axle carrier typically requires the addition of a boss or a pad to the carrier casting and additional machining operations to mount the sensor thereon. Specifically, a milling operation is often employed to xe2x80x9cfacexe2x80x9d the boss and provide a planar mounting pad. In addition, a hole must be drilled and subsequently tapped to create threads for mounting the sensor. Because the majority of carrier machining operations are performed within an automated machining line, the cost of adding tooling to perform the aforementioned machining operations may prove prohibitive.
Accordingly, it is an object of the present invention to minimize the cost of providing rear axle assemblies with anti-lock braking sensors.
It is another object of the present invention to reduce the number of machining operations performed on an axle carrier for an axle assembly equipped with an anti-lock braking system.
The present invention provides a driving axle assembly including an anti-lock braking system sensor, a carrier having an opening, a differential assembly having a housing rotatably mounted to the carrier and a cover pan mounted to the carrier to enclose the opening. The cover pan includes a boss having a generally planar mounting surface with an aperture therethrough. The anti-lock braking-system sensor is disposed within the aperture and coupled to the cover pan.
Further objects, features and advantages of the invention will become apparent from a consideration of the following description and the appended claims when taken in connection with the accompanying drawings.